1 - Or better yet, don't use any format at all. Go download-only, offer older games for download VC-style, and kill the used market dead. Terrible for consumers, but great for Sony.
2 - Honestly, I'm not sure price was the MAIN reason the PS3 failed, but there's no denying that it did a lot of harm. However, do keep in mind that the PS3 as we know it could not possibly have been offered at a price people were willing to pay for a game console; even as-is, Sony took crippling losses at first and still isn't out of the hole. This is what's known as overengineering, and it's why the PS3 was so expensive. This needs to be avoided.
3 - What you are suggesting is not, in fact, what Nintendo did. However, it ties in with #2 in a different way: they need to keep the tech on the PS4 within a reasonable level -i.e. something they can offer for a price people are willing to pay for a game console- without breaking the bank.
4 - Offering dev kits early on is indeed key, but they also need to be good tools. There is no reason that the PS3 should be as hard to develop for as the current developers claim, but Sony has been slow in offering them the things they really need to take advantage of the PS3's architectural quirks.
5 - This ties in with the point above. The hardware should not be a problem for developers; Sony has made it that way.
6 - Ultimately, this is the key to everything.
7 - Square-Enix clearly has some very good reasons to believe that an FFVII remake would be a bad idea. What those reasons are, I don't claim to know, but they've been quite adamant in sticking to them, going so far as to develop completely new games as spinoffs when a remake might actually be cheaper. How much would it take for Sony to overcome this apparent fear? Could Sony even afford to do it?
8 - Exclusives are key, this is true. Convincing companies to go exclusive is the problem. The fratcore simply cannot sustain the market by themselves anymore, especially not when they're so sharply divided between consoles. Devs have good reason to feel a need to go multiplatform, and Sony will have to find a way to overcome that.
9 - How much can it be improved while keeping it free? Services cost money to run, and that money has to come from somewhere. XBLA would probably cost a fair bit more were it not for the fact that Microsoft has almost infinite amounts of money to pour into the XBox division from outside.
10 - Coming out first only gave the XBox a bit of a head start in claiming what scraps of the market were left over after the Wii went on a rampage.
11 - Sony's marketing has indeed been made of fail. Even if the only thing they did different next gen was to stop insulting their own fanbase, they'd probably get a significant boost.
Complexity is not depth. Machismo is not maturity. Obsession is not dedication. Tedium is not challenge. Support gaming: support the Wii.
Be the ultimate ninja! Play Billy Vs. SNAKEMAN today! Poisson Village welcomes new players.
What do I hate about modern gaming? I hate tedium replacing challenge, complexity replacing depth, and domination replacing entertainment. I hate the outsourcing of mechanics to physics textbooks, art direction to photocopiers, and story to cheap Hollywood screenwriters. I hate the confusion of obsession with dedication, style with substance, new with gimmicky, old with obsolete, new with evolutionary, and old with time-tested.
There is much to hate about modern gaming. That is why I support the Wii.